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percpu-refcount: fix reference leak during percpu-atomic transition
[linux/fpc-iii.git] / crypto / algif_skcipher.c
blobc0f03562a1457d0199c94a2049d1531d0db0b418
1 /*
2 * algif_skcipher: User-space interface for skcipher algorithms
3 *
4 * This file provides the user-space API for symmetric key ciphers.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <crypto/scatterwalk.h>
16 #include <crypto/skcipher.h>
17 #include <crypto/if_alg.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/module.h>
23 #include <linux/net.h>
24 #include <net/sock.h>
25
26 struct skcipher_sg_list {
27 struct list_head list;
28
29 int cur;
30
31 struct scatterlist sg[0];
32 };
33
34 struct skcipher_tfm {
35 struct crypto_ablkcipher *skcipher;
36 bool has_key;
37 };
38
39 struct skcipher_ctx {
40 struct list_head tsgl;
41 struct af_alg_sgl rsgl;
42
43 void *iv;
44
45 struct af_alg_completion completion;
46
47 atomic_t inflight;
48 unsigned used;
49
50 unsigned int len;
51 bool more;
52 bool merge;
53 bool enc;
54
55 struct ablkcipher_request req;
56 };
57
58 struct skcipher_async_rsgl {
59 struct af_alg_sgl sgl;
60 struct list_head list;
61 };
62
63 struct skcipher_async_req {
64 struct kiocb *iocb;
65 struct skcipher_async_rsgl first_sgl;
66 struct list_head list;
67 struct scatterlist *tsg;
68 char iv[];
69 };
70
71 #define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
72 crypto_ablkcipher_reqsize(crypto_ablkcipher_reqtfm(&ctx->req)))
73
74 #define GET_REQ_SIZE(ctx) \
75 crypto_ablkcipher_reqsize(crypto_ablkcipher_reqtfm(&ctx->req))
76
77 #define GET_IV_SIZE(ctx) \
78 crypto_ablkcipher_ivsize(crypto_ablkcipher_reqtfm(&ctx->req))
79
80 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
81 sizeof(struct scatterlist) - 1)
82
83 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
84 {
85 struct skcipher_async_rsgl *rsgl, *tmp;
86 struct scatterlist *sgl;
87 struct scatterlist *sg;
88 int i, n;
89
90 list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
91 af_alg_free_sg(&rsgl->sgl);
92 if (rsgl != &sreq->first_sgl)
93 kfree(rsgl);
94 }
95 sgl = sreq->tsg;
96 n = sg_nents(sgl);
97 for_each_sg(sgl, sg, n, i)
98 put_page(sg_page(sg));
99
100 kfree(sreq->tsg);
101 }
102
103 static void skcipher_async_cb(struct crypto_async_request *req, int err)
104 {
105 struct sock *sk = req->data;
106 struct alg_sock *ask = alg_sk(sk);
107 struct skcipher_ctx *ctx = ask->private;
108 struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
109 struct kiocb *iocb = sreq->iocb;
110
111 atomic_dec(&ctx->inflight);
112 skcipher_free_async_sgls(sreq);
113 kfree(req);
114 iocb->ki_complete(iocb, err, err);
115 }
116
117 static inline int skcipher_sndbuf(struct sock *sk)
118 {
119 struct alg_sock *ask = alg_sk(sk);
120 struct skcipher_ctx *ctx = ask->private;
121
122 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
123 ctx->used, 0);
124 }
125
126 static inline bool skcipher_writable(struct sock *sk)
127 {
128 return PAGE_SIZE <= skcipher_sndbuf(sk);
129 }
130
131 static int skcipher_alloc_sgl(struct sock *sk)
132 {
133 struct alg_sock *ask = alg_sk(sk);
134 struct skcipher_ctx *ctx = ask->private;
135 struct skcipher_sg_list *sgl;
136 struct scatterlist *sg = NULL;
137
138 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
139 if (!list_empty(&ctx->tsgl))
140 sg = sgl->sg;
141
142 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
143 sgl = sock_kmalloc(sk, sizeof(*sgl) +
144 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
145 GFP_KERNEL);
146 if (!sgl)
147 return -ENOMEM;
148
149 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
150 sgl->cur = 0;
151
152 if (sg)
153 scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
154
155 list_add_tail(&sgl->list, &ctx->tsgl);
156 }
157
158 return 0;
159 }
160
161 static void skcipher_pull_sgl(struct sock *sk, int used, int put)
162 {
163 struct alg_sock *ask = alg_sk(sk);
164 struct skcipher_ctx *ctx = ask->private;
165 struct skcipher_sg_list *sgl;
166 struct scatterlist *sg;
167 int i;
168
169 while (!list_empty(&ctx->tsgl)) {
170 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
171 list);
172 sg = sgl->sg;
173
174 for (i = 0; i < sgl->cur; i++) {
175 int plen = min_t(int, used, sg[i].length);
176
177 if (!sg_page(sg + i))
178 continue;
179
180 sg[i].length -= plen;
181 sg[i].offset += plen;
182
183 used -= plen;
184 ctx->used -= plen;
185
186 if (sg[i].length)
187 return;
188 if (put)
189 put_page(sg_page(sg + i));
190 sg_assign_page(sg + i, NULL);
191 }
192
193 list_del(&sgl->list);
194 sock_kfree_s(sk, sgl,
195 sizeof(*sgl) + sizeof(sgl->sg[0]) *
196 (MAX_SGL_ENTS + 1));
197 }
198
199 if (!ctx->used)
200 ctx->merge = 0;
201 }
202
203 static void skcipher_free_sgl(struct sock *sk)
204 {
205 struct alg_sock *ask = alg_sk(sk);
206 struct skcipher_ctx *ctx = ask->private;
207
208 skcipher_pull_sgl(sk, ctx->used, 1);
209 }
210
211 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
212 {
213 long timeout;
214 DEFINE_WAIT(wait);
215 int err = -ERESTARTSYS;
216
217 if (flags & MSG_DONTWAIT)
218 return -EAGAIN;
219
220 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
221
222 for (;;) {
223 if (signal_pending(current))
224 break;
225 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
226 timeout = MAX_SCHEDULE_TIMEOUT;
227 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
228 err = 0;
229 break;
230 }
231 }
232 finish_wait(sk_sleep(sk), &wait);
233
234 return err;
235 }
236
237 static void skcipher_wmem_wakeup(struct sock *sk)
238 {
239 struct socket_wq *wq;
240
241 if (!skcipher_writable(sk))
242 return;
243
244 rcu_read_lock();
245 wq = rcu_dereference(sk->sk_wq);
246 if (wq_has_sleeper(wq))
247 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
248 POLLRDNORM |
249 POLLRDBAND);
250 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
251 rcu_read_unlock();
252 }
253
254 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
255 {
256 struct alg_sock *ask = alg_sk(sk);
257 struct skcipher_ctx *ctx = ask->private;
258 long timeout;
259 DEFINE_WAIT(wait);
260 int err = -ERESTARTSYS;
261
262 if (flags & MSG_DONTWAIT) {
263 return -EAGAIN;
264 }
265
266 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
267
268 for (;;) {
269 if (signal_pending(current))
270 break;
271 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
272 timeout = MAX_SCHEDULE_TIMEOUT;
273 if (sk_wait_event(sk, &timeout, ctx->used)) {
274 err = 0;
275 break;
276 }
277 }
278 finish_wait(sk_sleep(sk), &wait);
279
280 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
281
282 return err;
283 }
284
285 static void skcipher_data_wakeup(struct sock *sk)
286 {
287 struct alg_sock *ask = alg_sk(sk);
288 struct skcipher_ctx *ctx = ask->private;
289 struct socket_wq *wq;
290
291 if (!ctx->used)
292 return;
293
294 rcu_read_lock();
295 wq = rcu_dereference(sk->sk_wq);
296 if (wq_has_sleeper(wq))
297 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
298 POLLRDNORM |
299 POLLRDBAND);
300 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
301 rcu_read_unlock();
302 }
303
304 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
305 size_t size)
306 {
307 struct sock *sk = sock->sk;
308 struct alg_sock *ask = alg_sk(sk);
309 struct skcipher_ctx *ctx = ask->private;
310 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
311 unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
312 struct skcipher_sg_list *sgl;
313 struct af_alg_control con = {};
314 long copied = 0;
315 bool enc = 0;
316 bool init = 0;
317 int err;
318 int i;
319
320 if (msg->msg_controllen) {
321 err = af_alg_cmsg_send(msg, &con);
322 if (err)
323 return err;
324
325 init = 1;
326 switch (con.op) {
327 case ALG_OP_ENCRYPT:
328 enc = 1;
329 break;
330 case ALG_OP_DECRYPT:
331 enc = 0;
332 break;
333 default:
334 return -EINVAL;
335 }
336
337 if (con.iv && con.iv->ivlen != ivsize)
338 return -EINVAL;
339 }
340
341 err = -EINVAL;
342
343 lock_sock(sk);
344 if (!ctx->more && ctx->used)
345 goto unlock;
346
347 if (init) {
348 ctx->enc = enc;
349 if (con.iv)
350 memcpy(ctx->iv, con.iv->iv, ivsize);
351 }
352
353 while (size) {
354 struct scatterlist *sg;
355 unsigned long len = size;
356 int plen;
357
358 if (ctx->merge) {
359 sgl = list_entry(ctx->tsgl.prev,
360 struct skcipher_sg_list, list);
361 sg = sgl->sg + sgl->cur - 1;
362 len = min_t(unsigned long, len,
363 PAGE_SIZE - sg->offset - sg->length);
364
365 err = memcpy_from_msg(page_address(sg_page(sg)) +
366 sg->offset + sg->length,
367 msg, len);
368 if (err)
369 goto unlock;
370
371 sg->length += len;
372 ctx->merge = (sg->offset + sg->length) &
373 (PAGE_SIZE - 1);
374
375 ctx->used += len;
376 copied += len;
377 size -= len;
378 continue;
379 }
380
381 if (!skcipher_writable(sk)) {
382 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
383 if (err)
384 goto unlock;
385 }
386
387 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
388
389 err = skcipher_alloc_sgl(sk);
390 if (err)
391 goto unlock;
392
393 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
394 sg = sgl->sg;
395 if (sgl->cur)
396 sg_unmark_end(sg + sgl->cur - 1);
397 do {
398 i = sgl->cur;
399 plen = min_t(int, len, PAGE_SIZE);
400
401 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
402 err = -ENOMEM;
403 if (!sg_page(sg + i))
404 goto unlock;
405
406 err = memcpy_from_msg(page_address(sg_page(sg + i)),
407 msg, plen);
408 if (err) {
409 __free_page(sg_page(sg + i));
410 sg_assign_page(sg + i, NULL);
411 goto unlock;
412 }
413
414 sg[i].length = plen;
415 len -= plen;
416 ctx->used += plen;
417 copied += plen;
418 size -= plen;
419 sgl->cur++;
420 } while (len && sgl->cur < MAX_SGL_ENTS);
421
422 if (!size)
423 sg_mark_end(sg + sgl->cur - 1);
424
425 ctx->merge = plen & (PAGE_SIZE - 1);
426 }
427
428 err = 0;
429
430 ctx->more = msg->msg_flags & MSG_MORE;
431
432 unlock:
433 skcipher_data_wakeup(sk);
434 release_sock(sk);
435
436 return copied ?: err;
437 }
438
439 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
440 int offset, size_t size, int flags)
441 {
442 struct sock *sk = sock->sk;
443 struct alg_sock *ask = alg_sk(sk);
444 struct skcipher_ctx *ctx = ask->private;
445 struct skcipher_sg_list *sgl;
446 int err = -EINVAL;
447
448 if (flags & MSG_SENDPAGE_NOTLAST)
449 flags |= MSG_MORE;
450
451 lock_sock(sk);
452 if (!ctx->more && ctx->used)
453 goto unlock;
454
455 if (!size)
456 goto done;
457
458 if (!skcipher_writable(sk)) {
459 err = skcipher_wait_for_wmem(sk, flags);
460 if (err)
461 goto unlock;
462 }
463
464 err = skcipher_alloc_sgl(sk);
465 if (err)
466 goto unlock;
467
468 ctx->merge = 0;
469 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
470
471 if (sgl->cur)
472 sg_unmark_end(sgl->sg + sgl->cur - 1);
473
474 sg_mark_end(sgl->sg + sgl->cur);
475 get_page(page);
476 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
477 sgl->cur++;
478 ctx->used += size;
479
480 done:
481 ctx->more = flags & MSG_MORE;
482
483 unlock:
484 skcipher_data_wakeup(sk);
485 release_sock(sk);
486
487 return err ?: size;
488 }
489
490 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
491 {
492 struct skcipher_sg_list *sgl;
493 struct scatterlist *sg;
494 int nents = 0;
495
496 list_for_each_entry(sgl, &ctx->tsgl, list) {
497 sg = sgl->sg;
498
499 while (!sg->length)
500 sg++;
501
502 nents += sg_nents(sg);
503 }
504 return nents;
505 }
506
507 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
508 int flags)
509 {
510 struct sock *sk = sock->sk;
511 struct alg_sock *ask = alg_sk(sk);
512 struct skcipher_ctx *ctx = ask->private;
513 struct skcipher_sg_list *sgl;
514 struct scatterlist *sg;
515 struct skcipher_async_req *sreq;
516 struct ablkcipher_request *req;
517 struct skcipher_async_rsgl *last_rsgl = NULL;
518 unsigned int txbufs = 0, len = 0, tx_nents = skcipher_all_sg_nents(ctx);
519 unsigned int reqlen = sizeof(struct skcipher_async_req) +
520 GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
521 int err = -ENOMEM;
522 bool mark = false;
523
524 lock_sock(sk);
525 req = kmalloc(reqlen, GFP_KERNEL);
526 if (unlikely(!req))
527 goto unlock;
528
529 sreq = GET_SREQ(req, ctx);
530 sreq->iocb = msg->msg_iocb;
531 memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl));
532 INIT_LIST_HEAD(&sreq->list);
533 sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
534 if (unlikely(!sreq->tsg)) {
535 kfree(req);
536 goto unlock;
537 }
538 sg_init_table(sreq->tsg, tx_nents);
539 memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
540 ablkcipher_request_set_tfm(req, crypto_ablkcipher_reqtfm(&ctx->req));
541 ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
542 skcipher_async_cb, sk);
543
544 while (iov_iter_count(&msg->msg_iter)) {
545 struct skcipher_async_rsgl *rsgl;
546 int used;
547
548 if (!ctx->used) {
549 err = skcipher_wait_for_data(sk, flags);
550 if (err)
551 goto free;
552 }
553 sgl = list_first_entry(&ctx->tsgl,
554 struct skcipher_sg_list, list);
555 sg = sgl->sg;
556
557 while (!sg->length)
558 sg++;
559
560 used = min_t(unsigned long, ctx->used,
561 iov_iter_count(&msg->msg_iter));
562 used = min_t(unsigned long, used, sg->length);
563
564 if (txbufs == tx_nents) {
565 struct scatterlist *tmp;
566 int x;
567 /* Ran out of tx slots in async request
568 * need to expand */
569 tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
570 GFP_KERNEL);
571 if (!tmp)
572 goto free;
573
574 sg_init_table(tmp, tx_nents * 2);
575 for (x = 0; x < tx_nents; x++)
576 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
577 sreq->tsg[x].length,
578 sreq->tsg[x].offset);
579 kfree(sreq->tsg);
580 sreq->tsg = tmp;
581 tx_nents *= 2;
582 mark = true;
583 }
584 /* Need to take over the tx sgl from ctx
585 * to the asynch req - these sgls will be freed later */
586 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
587 sg->offset);
588
589 if (list_empty(&sreq->list)) {
590 rsgl = &sreq->first_sgl;
591 list_add_tail(&rsgl->list, &sreq->list);
592 } else {
593 rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
594 if (!rsgl) {
595 err = -ENOMEM;
596 goto free;
597 }
598 list_add_tail(&rsgl->list, &sreq->list);
599 }
600
601 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
602 err = used;
603 if (used < 0)
604 goto free;
605 if (last_rsgl)
606 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
607
608 last_rsgl = rsgl;
609 len += used;
610 skcipher_pull_sgl(sk, used, 0);
611 iov_iter_advance(&msg->msg_iter, used);
612 }
613
614 if (mark)
615 sg_mark_end(sreq->tsg + txbufs - 1);
616
617 ablkcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
618 len, sreq->iv);
619 err = ctx->enc ? crypto_ablkcipher_encrypt(req) :
620 crypto_ablkcipher_decrypt(req);
621 if (err == -EINPROGRESS) {
622 atomic_inc(&ctx->inflight);
623 err = -EIOCBQUEUED;
624 goto unlock;
625 }
626 free:
627 skcipher_free_async_sgls(sreq);
628 kfree(req);
629 unlock:
630 skcipher_wmem_wakeup(sk);
631 release_sock(sk);
632 return err;
633 }
634
635 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
636 int flags)
637 {
638 struct sock *sk = sock->sk;
639 struct alg_sock *ask = alg_sk(sk);
640 struct skcipher_ctx *ctx = ask->private;
641 unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
642 &ctx->req));
643 struct skcipher_sg_list *sgl;
644 struct scatterlist *sg;
645 int err = -EAGAIN;
646 int used;
647 long copied = 0;
648
649 lock_sock(sk);
650 while (msg_data_left(msg)) {
651 sgl = list_first_entry(&ctx->tsgl,
652 struct skcipher_sg_list, list);
653 sg = sgl->sg;
654
655 while (!sg->length)
656 sg++;
657
658 if (!ctx->used) {
659 err = skcipher_wait_for_data(sk, flags);
660 if (err)
661 goto unlock;
662 }
663
664 used = min_t(unsigned long, ctx->used, msg_data_left(msg));
665
666 used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
667 err = used;
668 if (err < 0)
669 goto unlock;
670
671 if (ctx->more || used < ctx->used)
672 used -= used % bs;
673
674 err = -EINVAL;
675 if (!used)
676 goto free;
677
678 ablkcipher_request_set_crypt(&ctx->req, sg,
679 ctx->rsgl.sg, used,
680 ctx->iv);
681
682 err = af_alg_wait_for_completion(
683 ctx->enc ?
684 crypto_ablkcipher_encrypt(&ctx->req) :
685 crypto_ablkcipher_decrypt(&ctx->req),
686 &ctx->completion);
687
688 free:
689 af_alg_free_sg(&ctx->rsgl);
690
691 if (err)
692 goto unlock;
693
694 copied += used;
695 skcipher_pull_sgl(sk, used, 1);
696 iov_iter_advance(&msg->msg_iter, used);
697 }
698
699 err = 0;
700
701 unlock:
702 skcipher_wmem_wakeup(sk);
703 release_sock(sk);
704
705 return copied ?: err;
706 }
707
708 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
709 size_t ignored, int flags)
710 {
711 return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
712 skcipher_recvmsg_async(sock, msg, flags) :
713 skcipher_recvmsg_sync(sock, msg, flags);
714 }
715
716 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
717 poll_table *wait)
718 {
719 struct sock *sk = sock->sk;
720 struct alg_sock *ask = alg_sk(sk);
721 struct skcipher_ctx *ctx = ask->private;
722 unsigned int mask;
723
724 sock_poll_wait(file, sk_sleep(sk), wait);
725 mask = 0;
726
727 if (ctx->used)
728 mask |= POLLIN | POLLRDNORM;
729
730 if (skcipher_writable(sk))
731 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
732
733 return mask;
734 }
735
736 static struct proto_ops algif_skcipher_ops = {
737 .family = PF_ALG,
738
739 .connect = sock_no_connect,
740 .socketpair = sock_no_socketpair,
741 .getname = sock_no_getname,
742 .ioctl = sock_no_ioctl,
743 .listen = sock_no_listen,
744 .shutdown = sock_no_shutdown,
745 .getsockopt = sock_no_getsockopt,
746 .mmap = sock_no_mmap,
747 .bind = sock_no_bind,
748 .accept = sock_no_accept,
749 .setsockopt = sock_no_setsockopt,
750
751 .release = af_alg_release,
752 .sendmsg = skcipher_sendmsg,
753 .sendpage = skcipher_sendpage,
754 .recvmsg = skcipher_recvmsg,
755 .poll = skcipher_poll,
756 };
757
758 static int skcipher_check_key(struct socket *sock)
759 {
760 int err = 0;
761 struct sock *psk;
762 struct alg_sock *pask;
763 struct skcipher_tfm *tfm;
764 struct sock *sk = sock->sk;
765 struct alg_sock *ask = alg_sk(sk);
766
767 lock_sock(sk);
768 if (ask->refcnt)
769 goto unlock_child;
770
771 psk = ask->parent;
772 pask = alg_sk(ask->parent);
773 tfm = pask->private;
774
775 err = -ENOKEY;
776 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
777 if (!tfm->has_key)
778 goto unlock;
779
780 if (!pask->refcnt++)
781 sock_hold(psk);
782
783 ask->refcnt = 1;
784 sock_put(psk);
785
786 err = 0;
787
788 unlock:
789 release_sock(psk);
790 unlock_child:
791 release_sock(sk);
792
793 return err;
794 }
795
796 static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
797 size_t size)
798 {
799 int err;
800
801 err = skcipher_check_key(sock);
802 if (err)
803 return err;
804
805 return skcipher_sendmsg(sock, msg, size);
806 }
807
808 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
809 int offset, size_t size, int flags)
810 {
811 int err;
812
813 err = skcipher_check_key(sock);
814 if (err)
815 return err;
816
817 return skcipher_sendpage(sock, page, offset, size, flags);
818 }
819
820 static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
821 size_t ignored, int flags)
822 {
823 int err;
824
825 err = skcipher_check_key(sock);
826 if (err)
827 return err;
828
829 return skcipher_recvmsg(sock, msg, ignored, flags);
830 }
831
832 static struct proto_ops algif_skcipher_ops_nokey = {
833 .family = PF_ALG,
834
835 .connect = sock_no_connect,
836 .socketpair = sock_no_socketpair,
837 .getname = sock_no_getname,
838 .ioctl = sock_no_ioctl,
839 .listen = sock_no_listen,
840 .shutdown = sock_no_shutdown,
841 .getsockopt = sock_no_getsockopt,
842 .mmap = sock_no_mmap,
843 .bind = sock_no_bind,
844 .accept = sock_no_accept,
845 .setsockopt = sock_no_setsockopt,
846
847 .release = af_alg_release,
848 .sendmsg = skcipher_sendmsg_nokey,
849 .sendpage = skcipher_sendpage_nokey,
850 .recvmsg = skcipher_recvmsg_nokey,
851 .poll = skcipher_poll,
852 };
853
854 static void *skcipher_bind(const char *name, u32 type, u32 mask)
855 {
856 struct skcipher_tfm *tfm;
857 struct crypto_ablkcipher *skcipher;
858
859 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
860 if (!tfm)
861 return ERR_PTR(-ENOMEM);
862
863 skcipher = crypto_alloc_ablkcipher(name, type, mask);
864 if (IS_ERR(skcipher)) {
865 kfree(tfm);
866 return ERR_CAST(skcipher);
867 }
868
869 tfm->skcipher = skcipher;
870
871 return tfm;
872 }
873
874 static void skcipher_release(void *private)
875 {
876 struct skcipher_tfm *tfm = private;
877
878 crypto_free_ablkcipher(tfm->skcipher);
879 kfree(tfm);
880 }
881
882 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
883 {
884 struct skcipher_tfm *tfm = private;
885 int err;
886
887 err = crypto_ablkcipher_setkey(tfm->skcipher, key, keylen);
888 tfm->has_key = !err;
889
890 return err;
891 }
892
893 static void skcipher_wait(struct sock *sk)
894 {
895 struct alg_sock *ask = alg_sk(sk);
896 struct skcipher_ctx *ctx = ask->private;
897 int ctr = 0;
898
899 while (atomic_read(&ctx->inflight) && ctr++ < 100)
900 msleep(100);
901 }
902
903 static void skcipher_sock_destruct(struct sock *sk)
904 {
905 struct alg_sock *ask = alg_sk(sk);
906 struct skcipher_ctx *ctx = ask->private;
907 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
908
909 if (atomic_read(&ctx->inflight))
910 skcipher_wait(sk);
911
912 skcipher_free_sgl(sk);
913 sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
914 sock_kfree_s(sk, ctx, ctx->len);
915 af_alg_release_parent(sk);
916 }
917
918 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
919 {
920 struct skcipher_ctx *ctx;
921 struct alg_sock *ask = alg_sk(sk);
922 struct skcipher_tfm *tfm = private;
923 struct crypto_ablkcipher *skcipher = tfm->skcipher;
924 unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(skcipher);
925
926 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
927 if (!ctx)
928 return -ENOMEM;
929
930 ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(skcipher),
931 GFP_KERNEL);
932 if (!ctx->iv) {
933 sock_kfree_s(sk, ctx, len);
934 return -ENOMEM;
935 }
936
937 memset(ctx->iv, 0, crypto_ablkcipher_ivsize(skcipher));
938
939 INIT_LIST_HEAD(&ctx->tsgl);
940 ctx->len = len;
941 ctx->used = 0;
942 ctx->more = 0;
943 ctx->merge = 0;
944 ctx->enc = 0;
945 atomic_set(&ctx->inflight, 0);
946 af_alg_init_completion(&ctx->completion);
947
948 ask->private = ctx;
949
950 ablkcipher_request_set_tfm(&ctx->req, skcipher);
951 ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
952 af_alg_complete, &ctx->completion);
953
954 sk->sk_destruct = skcipher_sock_destruct;
955
956 return 0;
957 }
958
959 static int skcipher_accept_parent(void *private, struct sock *sk)
960 {
961 struct skcipher_tfm *tfm = private;
962
963 if (!tfm->has_key)
964 return -ENOKEY;
965
966 return skcipher_accept_parent_nokey(private, sk);
967 }
968
969 static const struct af_alg_type algif_type_skcipher = {
970 .bind = skcipher_bind,
971 .release = skcipher_release,
972 .setkey = skcipher_setkey,
973 .accept = skcipher_accept_parent,
974 .accept_nokey = skcipher_accept_parent_nokey,
975 .ops = &algif_skcipher_ops,
976 .ops_nokey = &algif_skcipher_ops_nokey,
977 .name = "skcipher",
978 .owner = THIS_MODULE
979 };
980
981 static int __init algif_skcipher_init(void)
982 {
983 return af_alg_register_type(&algif_type_skcipher);
984 }
985
986 static void __exit algif_skcipher_exit(void)
987 {
988 int err = af_alg_unregister_type(&algif_type_skcipher);
989 BUG_ON(err);
990 }
991
992 module_init(algif_skcipher_init);
993 module_exit(algif_skcipher_exit);
994 MODULE_LICENSE("GPL");
Linux with added FPC-III support